A CAN-type semiconductor laser device is one type of semiconductor laser devices. The CAN-type semiconductor laser device has a pedestal, a semiconductor laser mounted on the pedestal, a metal cap covering the semiconductor laser, and a plurality of lead pins electrically connected to the semiconductor laser. In other words, a semiconductor laser is housed in a metal container made up of a pedestal and a cap. In the following descriptions, the CAN-type semiconductor laser device as described above is referred to as “CAN-package semiconductor laser”.
Since the CAN-package semiconductor laser is used as, for example, a light source of an optical communication module (Japanese Patent Application Laid-Open Publication No. 2008-85259 (Patent Document 1)), the size reduction thereof is required for the improvement of transmission characteristics. Concretely, in order to reduce the transmission loss by shortening the signal transmission distance as much as possible, lead pins, bonding wires and others need to be shortened. For example, the CAN-package semiconductor laser called “TO-56 CAN” which is now in widespread use has a diameter of about 5.6 mm and a height of 3 to 4 mm. However, it is expected that a CAN-package semiconductor laser smaller than the TO-56 CAN and other CAN-package semiconductor lasers is developed and put to practical use according to the requirement mentioned above.